A. Must mustn't needn't
'You
must do something' = it is necessary that you do it:
* Don't
tell anybody what I said. You must keep it a secret.
* We
haven't got much time. We must hurry.
'You
mustn't do something' = it is necessary that you do not do it (so don't do it):
* You
must keep it a secret. You mustn't tell anybody else. (= don't tell anybody
else)
* It's
essential that nobody hears us. We mustn't make any noise.
'You
needn't do something' = it is not necessary that you do it, you don't need to
do it:
* You
can come with me if you like but you needn't come if you don't want to. (= it
is not necessary for you to come)
* We've
got plenty of time. We needn't hurry. (= it is not necessary to hurry)
B.
Instead of needn't, you can use don't/doesn't need to. So you can say:
* We
needn't hurry. or We don't need to hurry.
Remember
that we say 'don't need to do', but 'needn't do' (without to).
Needn't
and don't need to are similar to don't have to (see Unit 31C):
* We've
got plenty of time. We don't have to hurry.
C.
Needn't have (done)
Study
this example situation:
I think
it's going to rain. I'll take the umbrella.
I
needn't have brought the umbrella.
George
had to go out. He thought it was going to rain, so he decided to take the
umbrella.
But it
didn't rain, so the umbrella was not necessary. So:
He
needn't have taken the umbrella.
'He
needn't have taken the umbrella' = He took the umbrella but this was not necessary.
Of course, he didn't know this when he went out.
Compare
needn't (do) and needn't have (done):
* That
shirt isn't dirty. You needn't wash it.
* Why
did you wash that shirt? It wasn't dirty. You needn't have washed it.
D.
Didn't need to (do) and needn't have (done)
I didn't
need to ... = it was not necessary for me to... (and I knew this at the time):
* I
didn't need to get up early, so I didn't.
* I
didn't need to get up early, but it was a lovely morning, so I did.
'I
needn't have (done) something' = I did something but now I know that it was not
necessary:
* I got
up very early because I had to get ready to go away. But in fact it didn't take
me long to get ready. So, I needn't have got up so early. I could have stayed
in bed longer.
EXERCISES
32.1
Complete the sentences using needn't + one of these verbs:
ask come
explain leave tell
walk
1. We've
got plenty of time. We _needn't leave_ yet.
2. I can
manage the shopping alone. You --- with me.
3. We
--- all the way home. We can get a taxi.
4. just
help yourself if you'd like something to eat. You --- first.
5. We
can keep this a secret between ourselves. We --- anybody else.
6. I
understand the situation perfectly. You --- further.
32.2
Complete the sentences with must, mustn't or needn't.
1. We
haven't got much time. We _must_ hurry.
2. We've
got plenty of time. We _needn't_ hurry.
3. We
have enough food at home so we --- go shopping today.
4. Jim
gave me a letter to post. I --- remember to post it.
5. Jim
gave me a letter to post. I --- forget to post it.
6.
There's plenty of time for you to make up your mind. You --- decide now.
7. You
--- wash those tomatoes. They've already been washed.
8. This
is a valuable book. You --- look after it carefully and you ---lose it.
9. 'What
sort of house do you want to buy? Something big?' 'Well, it --- be big--that's
not important. But it --- have a nice garden--that's essential.'
32.3
Read the situations and make sentences with needn't have.
1.
George went out. He took an umbrella because he thought it was going to rain.
But it didn't rain. He needn't have taken an umbrella.
2. Ann
bought some eggs when she went shopping. When she got home, she found that she
already had plenty of eggs. She ---.
3. A
friend got angry with you and shouted at you. You think this was unnecessary.
Later you say to him/her: You ---.
4. Brian
had no money, so he sold his car. A few days later he won some money in a
lottery. He ---.
5. When
we went on holiday, we took the camera with us but we didn't use it in the end.
---.
6. I
thought I was going to miss my train so I rushed to the station. But the train
was late and in the end I had to wait 20 minutes. ---.
32.4
Write two sentences for each situation. Use needn't have in the first sentence
and could have in the second (as in the example). For could have see Unit 27.
1. Why
did you rush? Why didn't you take your time?
_You
needn't have rushed. You could have taken your time._
2. Why
did you walk home? Why didn't you take a taxi?
3. Why
did you stay at a hotel? Why didn't you stay with us?
4. Why
did she phone me in the middle of the night? Why didn't she phone me in the
morning?
5. Why
did you leave without saying anything? Why didn't you say goodbye to me?
the answer
32.1
2
needn't come
3
needn't walk
4
needn't ask
5
needn't tell
6
needn't explain
32.2
3
needn't
4 must
5
mustn't
6
needn't
7
needn't
8 must
... mustn't
9
needn't ... must
32.3
2 She
needn't have bought any eggs.
3 You
needn't have shouted (at me).
4 He
needn't have sold his car.
5 We
needn't have taken the camera.
6 I
needn't have rushed/I needn't have hurried.
32.4
2 You
needn't have walked home. You could have taken a taxi.
3 You
needn't have stayed at a hotel. You could have stayed with us.
4 She
needn't have phoned me in the middle of the night, She could have phoned me in
the morning.
5 You
needn't have left without saying anything. You could have said goodbye to me.
